As shown in FIG. 1, an example of a basic structure of vacuum glazing is illustrated. Specifically, a gap with a height of h is formed between an upper glass sheet 5 and a lower glass sheet 4 through pillars 3 arranged therebetween. A glass solder 1, the upper glass sheet 5 and the lower glass sheet 4 together forma cavity layer 2 (i.e. a vacuum layer to be achieved) after sealing the edges of the upper glass sheet 5 and the lower glass sheet 4 by using the glass solder 1. After pumping out the air inside the cavity layer 2 via a pump-out hole 41, the vacuum layer is formed. Then, a sealing sheet 53 is used to seal the pump-out hole 41 (for example, through combining the sealing sheet 53 and the lower glass sheet 4 into a whole by means of sintering or fusing a sealing solder 51). As a preferred but not restrictive example, a Low-E film 8 may be attached onto the inner side of at least one of the upper glass sheet 5 and the lower glass sheet 4 (for example, the lower glass sheet 4), and an encapsulated getter 40 may also be placed in the pump-out hole 41.
In addition to the above described structural features, it mainly depends on the completeness of the edge sealing, complete vacuum pumping, and reliable sealing of the pump-out hole to achieve physical vacuum properties of the vacuum glazing. Accordingly, a number of techniques have been developed and used in the manufacturing systems/production lines for manufacturing vacuum glazing. For example,
CN 101234847A: Continuous vacuum glazing edge sealing furnace
CN 1286670A: Method and device for manufacturing vacuum glazing
CN 201071341Y: Continuous fusion-sealing and vacuum-pumping glazing processing apparatus
CN 101348326A: Continuous production method and apparatus of vacuum glazing
CN 102030464A: Continuous production apparatus of vacuum glazing
KR 10-2012-0009788: Vacuum glazing, a manufacturing method and a system thereof
The disclosures of all the literatures described above will be incorporated herein by reference in their entirety, serving as the existing background art, prior to the present application, of vacuum glazing pumping and sealing by using a continuous/discontinuous vacuum furnace in a vacuum glazing manufacturing system.
Although the above described literatures have disclosed some beneficial teachings, in actual practice, there are still various technical problems to be solved. For example, it is difficult for a continuous vacuum furnace to achieve rapid and uniform heating and cooling in a vacuum environment. Since devices of respective portions in a manufacturing system are associated with each other, a breakdown in a certain portion may lead to the failure of the entire production line, and its maintenance is complicated. As a result, the manufacturing system is of relatively poor overall coordination and low stability, thereby increasing the cost of the product. In addition, it has to take both the pumping and sealing apparatus and the structure of the pump-out hole of the vacuum glazing into account during a design stage, thereby resulting in relatively complicated process and even incapable of achieving a real “continuous” production.
Specifically, the above background literatures CN 101348326A, CN 102030464A and KR 10-2012-0009788 are taken as examples, in which the processes of pre-pumping, edge sealing, vacuum pumping and pump-out hole sealing are performed in different processing stages from the processing stages relating to achieving vacuum properties. Since different environmental temperatures are required in these different processing stages, it has to wait a considerable long time to perform a heating or a cooling process in transiting from one processing stage to another one. Further, because the pumping device, the vacuum pumping device and the hole sealing device used in different processing stages are operated alternately, corresponding processes, which are technically difficult and time-consuming, are needed to align the corresponding devices with the pump-out hole, respectively. Thus, with regard to the so-called “continuous” processing in the above described background art, it is a desire difficult to be achieved no matter in time and/or in space.
More specifically, according to the existing techniques (for example, see FIG. 4 and the corresponding paragraph [0035] of the specification of the patent literature CN 102030454A serving as the background of the present invention), the chamber of the processing furnace, in which the entire volume of the glazing is accommodated, needs to be heated during the edge sealing processing stage of the vacuum glazing. The process of pre-pumping, vacuum pumping and hole sealing, however, are only related to the pump-out hole and its adjacent areas, thus, the overall heating/cooling operation performed on the entire volume of the glazing being processed and the vacuum pumping operation performed on the entire chamber of the processing furnace accommodating the entire volume of the glazing are a waste of time and energy sources.